From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 181C9C38A2A for ; Fri, 8 May 2020 14:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB3B620CC7 for ; Fri, 8 May 2020 14:31:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588948274; bh=rxJGu5drzSYlySe9vqiHE3VHx5o1VcEOkPGlZR8Lo3A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZCM6JTUlhHPZcWAKKlutGnKxis9Sqf+fj1dr//n16LIw2Sl5X5G79r89RWDNyIO7R U5yI/UmpntcKAM6SzJ3FiGjnCJ2vfmVJyKJ+B5uGPJgWqR8jXXvvQxe+Emhe4h9unM ZkYjxij7fNQtanddXiIgmenn8N72VtpwIaGKz6Ig= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgEHObO (ORCPT ); Fri, 8 May 2020 10:31:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:57206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726767AbgEHObN (ORCPT ); Fri, 8 May 2020 10:31:13 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B3C622083B; Fri, 8 May 2020 14:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588948273; bh=rxJGu5drzSYlySe9vqiHE3VHx5o1VcEOkPGlZR8Lo3A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=wZktF9m7g8nYEa9ZRPbOPppcX55CdaEXNGt4tq/QwNaZjeCd3Cx9CY1afEGvZbEy/ 5VqH9lwxCpoFVdnXPDOTHakZAl448yXKr/oFjO6K3GMG5lHxpfgA2cIE4ZHTqXrs7A J9uT/dzg4LEAEYZUZ3rPBSdjCD2CNsjk8P3MYEbg= Date: Fri, 8 May 2020 16:31:10 +0200 From: Greg KH To: Tang Bin Cc: stern@rowland.harvard.edu, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Zhang Shengju Subject: Re: [PATCH] USB: host: ehci: Add error handling inehci_mxc_drv_probe() Message-ID: <20200508143110.GA447591@kroah.com> References: <20200508114453.15436-1-tangbin@cmss.chinamobile.com> <20200508114858.GA4085349@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 08, 2020 at 09:55:53PM +0800, Tang Bin wrote: > Hi, Greg: > > On 2020/5/8 19:48, Greg KH wrote: > > On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote: > > > The function ehci_mxc_drv_probe() does not perform sufficient error > > > checking after executing platform_get_irq(), thus fix it. > > > > > > Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards") > > > Signed-off-by: Zhang Shengju > > > Signed-off-by: Tang Bin > > > --- > > > drivers/usb/host/ehci-mxc.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c > > > index a1eb5ee77..a0b42ba59 100644 > > > --- a/drivers/usb/host/ehci-mxc.c > > > +++ b/drivers/usb/host/ehci-mxc.c > > > @@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev) > > > } > > > irq = platform_get_irq(pdev, 0); > > > + if (irq < 0) > > > + return irq; > > <= ? > > In the file 'drivers/base/platform.c'， the function platform_get_irq() is > explained and used as follows: > >      * Gets an IRQ for a platform device and prints an error message if > finding the >      * IRQ fails. Device drivers should check the return value for errors so > as to >      * not pass a negative integer value to the request_irq() APIs. >      * >      * Example: >      *        int irq = platform_get_irq(pdev, 0); >      *        if (irq < 0) >      *            return irq; >      * >      * Return: IRQ number on success, negative error number on failure. > > And in my hardware experiment, even if I set the irq failed deliberately in > the DTS, the returned value is negative instead of zero. Please read the thread at https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org for more details about this. thanks, greg k-h